There is known in the art a device for control of shut-off members (cf., U.S.S.R. Inventor's Certificate No. 508,630, class F 16 K 31/52, of May 11, 1973). Said prior art device lacks remote control, thereby precluding the possibility of its use with telemechanical systems and of operational control shut-off members, which results in a reduced reliability of control of the actuator of a shut-off member.
Also known in the art is a device for remote control of the actuator of a shut-off member, namely, EPUU-2 Electropneumatic Control Unit (cf., Catalogue "Systems and automatic means for installations of gas industry", Vsesojusnoye Nauchno Proizvodstvennoye Objedineniye "Soyuzgasavtomatika", Moscow, 1976) The device comprises three three-way valves, each having a manual drive and a solenoid.
The solenoids provide for the switching of the valves depending upon the inlet electrical control signal, each valve communicating the supply line of the device with the control line, or the control line with a line for the discharge of gas to the atmosphere. The device utilizes conveyed natural gas. More often than not, the quality of purification and drying of the natural gas is inadequate. At negative ambient temperatures, hydrate jams are formed in pulsed lines, valves and slide valves, which results in low reliability of operation and in misfiring, i.e., in a reduced reliability of control of the actuator of a shut-off member. This prior art device requires the provision of a drying filter and, consequently, for permanent servicing.
There is further known in the art a device for remote control of the drive of a shut-off member (cf., F.R.G. Pat. No. 2,264,463, class F 16 K 31/12, of Apr. 26, 1972), which comprises an autonomous source of energy in the form of an electrically driven supercharger and a distributor connected thereto. The device is remote-controlled, for which purpose the distributor fashioned as a pair of on-off slide valves is controlled electromagnetically. The presence of a supercharger with a non-return valve and additional container, distributing pipeline and electromagnetic control complicates the structure and, thereby, affects the reliability of control over the shut-off member. In addition, this prior art device requires a rather powerful and continuous input electrical signal and cannot operate from command pulses issued by telemechanical systems. This also reduces the reliability of control of a shut-off member. The prior art device requires permanent servicing in operation.